JPH0526895B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piping device for concrete placement, and more particularly to a piping device for concrete placement suitable for application to the tremie method of underwater concrete.

The tremie method is well known as an underwater concrete construction method. FIG. 1 is an explanatory diagram of the general tremie construction method. This method uses a pipe 10 called a tremie whose upper part is shaped like a funnel. As shown in FIG. 1a, the piping 10 is vertically installed in the water W, and its lower end is placed slightly away from the bottom E of the water. Next, as shown in b, a loose plug 12 called a plunger is inserted into the pipe 10,
Pour concrete C on top of it. Depending on the weight of the poured concrete C, the plug 12 is connected to the pipe 1.
As shown in c, the plug 12 and the concrete C are discharged from the lower end of the pipe 10 into the water W and are cast onto the water bottom E. d shows a state in which the pouring of the concrete C has progressed and the lower end of the pipe 10 is inserted into the concrete C that has already been poured.

The conventional tremie construction method described above had the following problems. The lower end of the pipe 10 is usually installed 20 to 30 cm away from the water bottom E to allow the concrete C to flow out. At the start of pouring the concrete C, the first concrete C is discharged from the lower end of the pipe 10 into the water W and falls through the water W, as shown in FIG. 1c. Concrete that falls into water is washed away by the water, and its constituent particles (cement, fine aggregate, coarse aggregate) separate and do not harden into concrete. Also, at this time, the separated cement is scattered into the water, significantly polluting the water quality.

Moreover, when concrete is poured to a predetermined height, the pipe 10 is pulled up and replaced. When the lower end of the pipe 10 comes out above the surface of the poured concrete when the pipe 10 is pulled up, the pipe 1
Concrete C that had accumulated inside 0 falls into the water W and is also washed away by the water. At this time, separation of concrete materials occurs, polluting the water quality.

Moreover, not only is the concrete discharged from the opening of the pipe 10 in a free state, but the discharge speed of the concrete cannot be controlled. For example, highly viscous concrete or hard-mixed concrete may cause problems such as difficulty in flowing out smoothly from the opening at the lower end of the pipe.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to freely control concrete discharge/stop or discharge speed when applied to underwater concrete construction such as the tremie method. An object of the present invention is to provide a piping device for concrete placement that can prevent material separation and water pollution caused by falling concrete into water.

In order to achieve the above object, the present invention provides a drive means for coupling a screw conveyor in the same direction to the lower end portion of piping disposed in the vertical direction, and driving means for rotationally driving the screw conveyor. and a control means for controlling the discharge and stop of the concrete by controlling the drive of the screw conveyor, and shielding the lower end of the screw conveyor to discharge the concrete from a position eccentric to the rotation axis of the screw conveyor. It is characterized by the provision of a shielding plate.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 shows a method of constructing underwater concrete using the piping device for concrete placement according to the present invention, and FIGS. 3 and 4 show the main structure of the piping device in detail.

As shown in FIGS. 2 and 3, the piping device for concrete pouring according to the present invention includes a piping 20 whose upper end is formed into a funnel shape, and a screw conveyor 30 connected to the lower end of this piping 20. It consists of The screw conveyor 30 is connected to the piping 2
An outer pipe 31 connected in the same direction as 0 and a motor 33 (driving means) housed inside a partition wall 32 at its upper end, and controlling the drive of this motor 33 to control discharge and stop of concrete. a control means (not shown), a rotating shaft 34 of the motor 33 supported at the center of the outer tube 31, a screw 35 provided integrally with the rotating shaft 34, and a power supply for the motor 33 pulled out upward. and control cable 36
It consists of

Further, as shown in FIG. 4, bulges 37 and 38 are integrally provided on the sides of both ends of the envelope tube 31, respectively. The bulging portion 37 forms an upper opening of the screw conveyor 30, and this opening is coupled to the lower end opening of the pipe 20. Further, the bulging portion 38 is connected to the screw conveyor 30.
A lower opening 39 is formed. In other words, the lower end of the center of the outer tube 31 (the part that supports the lower end of the rotating shaft 34) is closed by the shielding plate 40, and in order to discharge concrete from a position eccentric to the rotating shaft of the screw conveyor 30, that side An opening 39 is formed by the bulge 38 on one side.

Therefore, when concrete is poured into the pipe 20, the concrete is introduced into the outer periphery of the screw conveyor 30 from the opening at the lower end of the pipe 20. At this time, when the motor 33 is rotating in the forward direction, the concrete is conveyed by the screw 35 and forcibly guided downward, and the concrete is discharged from the opening 39 as it is force-fed laterally from the axial direction of the screw 35. be done.

If the motor 33 is stopped at this point, the outer pipe 3
1 is blocked by a shielding plate 40, the concrete poured into the pipe 20 is stopped at this screw conveyor 30,
Concrete does not flow out from the opening 39. In this way, the discharge and stop of concrete from the opening 39 can be controlled by rotating/stopping or reversing the motor 33, and the speed of concrete discharged from the opening 39 can be controlled by the rotational speed of the motor 33. I can do it.

Next, the underwater concrete construction method shown in FIG. 2 will be explained. First, as shown in a, the concrete casting piping device according to the present invention is vertically disposed in water W, with its lower end opening 39 appropriately spaced from the water bottom E. Next, as shown in b, concrete C is poured from the top of the pipe 20 with the motor 33 stopped. Since the concrete C is not discharged from the opening 39 when the motor 33 is stopped, the concrete C accumulates in the pipe 20 as shown in c. Therefore, the motor 33 is driven to rotate, and the concrete C in the pipe 20 is forcibly discharged from the opening 39 by the screw conveyor 30. At the start of this pouring, the rotational speed of the motor 33 is set to a low speed, and the concrete C is gradually discharged. By doing this, explosive discharge of concrete C is prevented, flow of concrete in water W is suppressed,
Separation of constituent particles of concrete and water pollution can be reduced.

Although not shown in FIG. 2, when the concrete C is poured to a predetermined height and the piping device is once pulled up and replaced, the motor 33 is pulled up with the motor 33 stopped. That is, when the motor 33 is stopped and the concrete C is pulled up without being discharged from the opening 39, the concrete C accumulated in the pipe 20 does not fall onto the pouring surface as in the conventional case. In addition, by controlling the rotational speed of the motor 33 when discharging concrete in accordance with the viscosity and degree of hardening of the concrete, concrete can be smoothly discharged at a desired speed.

In addition, during the above-mentioned underwater concrete construction, it is preferable to use concrete to which a mixture for reducing separation is added.

Next, other embodiments of the invention will be described. 5 and 6 show a second embodiment of the invention. In this embodiment, the lower end surface of the envelope tube 31 is closed with a shielding plate 40 as in the previous embodiment, but there is no lower bulge 38. The concrete pumped by the conveyor is discharged through an opening 43 formed in the shape of a window around the outer periphery of the lower end of the outer tube 31. In this case, the opening 43 on the outer periphery of the outer tube 31
Concrete will be discharged laterally from the Therefore, when constructing underwater concrete as shown in FIG.
Particularly, according to this embodiment, the initial concrete at the start of pouring does not fall into the water, which prevents the separation of constituent particles of concrete and water pollution. Great effect.

Furthermore, in each of the embodiments described above, a conventional tremie tube is used as the piping 20, and the screw conveyor 30 can be detachably connected to the lower end thereof. Therefore, the configuration of the device is simple, and it is easy to assemble and transport.

As explained in detail above, according to the concrete pouring piping device according to the present invention, concrete discharge/stop and discharge speed can be freely controlled, such as when constructing underwater concrete using the tremie method. can,
Separation of materials and water pollution caused by extreme free falling of concrete can be greatly reduced, and even if the pipe is pulled up when the screw conveyor stops rotating, the shielding plate prevents concrete from falling. Since concrete can be placed at different locations, it can be used continuously.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the underwater concrete construction method using the conventional general tremie method, Fig. 2 is an explanatory diagram of the underwater concrete construction method using the concrete placement piping device according to the present invention, and Fig. 3 is an explanatory diagram of the underwater concrete construction method using the conventional general tremie method. A main part configuration diagram of the first embodiment of the piping device for concrete pouring according to the invention, FIG. 4A is the same as A- in FIG. 3.
4B is a sectional view taken along line A, FIG. 4B is a view taken along arrow B in FIG. 3, FIG. 5 is a configuration diagram of a second embodiment of the present invention, and FIG. 20... Piping, 30... Screw conveyor,
31...Outer tube, 33...Motor, 35...Screw, 36...Cable, 37, 38...Bulging portion, 39...Opening, 40...Shielding plate, 41...Opening, 42... Support plate, 43...opening.

Claims (1)

[Claims] 1 A piping device that is arranged in the vertical direction and discharges concrete supplied from the upper part from the lower end for pouring, and a screw conveyor is connected to the lower end of the pipe arranged in the vertical direction in the same direction. , a drive means for rotationally driving the screw conveyor, and a control means for controlling the driving of the drive means to control discharging and stopping of the concrete, and a lower end of the screw conveyor is shielded so as to prevent the concrete from being discharged. A piping device for placing concrete, characterized in that a shielding plate is provided for discharging the concrete from a position eccentric to the rotation axis of a screw conveyor.